1. Field of Application
The invention relates to a balance practicing machine that provides a swinging motion to a person sitting on the machine in order to provide balance practice and exercise.
2. Description of the Related Art
The related art includes a type of conventional balance practicing machine which is constructed in the shape of a horse and equipped with six power sources that generate six different movements. An example of such a conventional balance practicing machine is described in Japanese Kokou Patent No. H6-65350. These six movements consist of repetitive linear motions in the fore-aft, right-left, and vertical directions, and repetitive pivoting motions around longitudinally, transversely, and vertically oriented shafts. These motions combine to form a compound swinging movement comprised of six separately controllable movements.
Another type of conventional balance practicing machine is shown in FIGS. 7 through 9. An example of this type of conventional balance practicing machine is described in Japanese Kokai (laid open) Patent 2001-286578. This machine is equipped with seat 2 on which a person sits, drive assembly 3 which imparts a swinging motion to seat 2, main shaft 30 of motor 10a that extends in the ‘A’ and ‘B’ directions, and output shafts 12a and 12b that provide power transmission to move seat 2 with a repetitive linear motion in the fore-aft X direction, a repetitive pivoting motion in a direction around transversely oriented shaft 7, and a repetitive pivoting motion in a direction around longitudinally oriented shaft 9. As FIG. 7 illustrates, torque supplied through output shaft 12a, which extends from one side of motor 10a, is transferred from gear 31 to gear 32, and rotates shaft 33 to which first crank 34 is attached to one end thereof. The rotation of first crank 34 is converted, through first rod 35, into concurrent forward and rearward pivoting motions of first link 36 and second link 38 around pivot pins 37 and 39, respectively, thus imparting forward and rearward motions to seat 2, through seat base 4, along with changes in the inclination of the upper surface of seat 2. The upper end of second link 38 is pivotably attached to seat base 4 through ball joint 71 so as to form a movable link there between, and the lower end is pivotably attached to base member 8 through support plate 70. The torque supplied by output shaft 12b, which extends from the other side of motor 10a, is transferred from gear 40 to gear 41 (FIG. 8) to rotate second crank 43 which is connected to one end of shaft 42 (FIG. 9). The rotation of second crank 43 imparts a repetitive pivoting motion to seat base 4 and seat 2, through second rod 44, in a direction around longitudinally oriented shaft 9.
Because the balance practicing machine described in Japanese Kokou Patent No. H6-65350 is equipped with six separately controlled power sources, the timing, speed, and operating range of each power source must be individually controlled, thus making for an extremely complex control system. Moreover, the use of six power sources increases both the cost and size of the balance practicing machine.
The balance practicing machine described in Japanese Kokai (laid open) Patent 2001-286578 incorporates output shaft 12 that extends in two opposing directions from motor 10a, thus requiring that motor 10a be installed horizontally. This structure creates a problem in that a large amount of space must be provided on the horizontal plane to accommodate the bi-direction extension of output shaft 12, and that drive assembly 3 be made to relatively large dimensions.